EEPOET OST THE POLYZOA. 
53 
(2) Diachoris crotcili, Busk. 
(3) Diachoris costatci, Busk (PI. XXXIV. fig. 4). 
(4) Diachoris inermis, Busk. 
(5) Diachoris hirtissima, Heller. 
§ A. Zocecia contiguous. 
§§ a. U trinque poroses, Linne. 
1. Flustra, Linne. 
Flustra, Bk., Brit. Mus. Cat., vol. i. p. 47. 
„ (sp.) Linn., Auctt ; Hincks, Brit. Mar. Polyz., vol. i. p. 114, § a. 
Eschara (pars), Pallas. 
Character. — Zooecia disposed in two inseparable layers (except when clecurrent). 
(1) Flustra crassa, n. sp. (PL XVI. fig. 6). 
Character. — Zoarium broadly lobate, very thick and fleshy. Zocecia elongated, oblong, 
entirely membranous in front ; a short conical point at each upper angle. Ooecium 
cucullate, erect. 
Habitat. — Station 149d, Royal Sound, Kerguelen Island, 28 fathoms, volcanic mud. 
Remarkable for its thick, almost fleshy consistence. 
(2) Flustra denticulata, Busk (PI. XXXII. fig. 2). 
Flustra denticulata , var. inermis , Bk., Brit. Mus. Cat., vol. i. p. 49, pi. xlix. figs. 3, 4. 
Character. — Zoarium composed of linear branches slightly expanding at the ends. 
Zocecia elongated pyriform, with a few very minute internal hooked spicules on each side, 
more especially towards the lower part. Avicularia rare, small, obliquely quadrangular, 
with an acute mandible placed obliquely. 
Habitat . — Station 163 a, lat. 36° 59' S., long. 150° 20' E., off Twofold Bay, 150 
fathoms, green mud. 
[New Zealand, Dr. Lyall,] 
The form denominated Flustra denticulata in the Brit. Mus. Cat., p. 49, described and 
figured, as it would seem, in the most fully developed condition (pi. lvii.), is one which 
presents considerable difficulty with respect to the varieties it exhibits. In the 
form shown in pi. lvii. ( loc . cit.), the border of the front is furnished with very 
remarkable tooth-like, usually bifid spines, which arch over the front, decussating more or 
